Substrate processing apparatus and substrate processing method

ABSTRACT

The present invention provides a substrate processing apparatus and a substrate processing method suitable for use in an etching apparatus which etches a thin film formed on a peripheral portion of a substrate. The present invention also provides a substrate processing apparatus and a substrate processing method suitable for use in a cleaning apparatus which performs a cleaning process on a substrate which has been etched. The substrate processing apparatus for use in etching includes a substrate holder  11  for holding a substrate W substantially horizontally and rotating the substrate W, and a processing liquid supply unit  15  for supplying a processing liquid onto a peripheral portion of the substrate W which is being rotated in such a manner that the processing liquid is stationary with respect to the substrate W. The substrate processing apparatus for use in cleaning a substrate includes a substrate holder  54  for holding a substrate W substantially horizontally and rotating the substrate W, and a cleaning liquid supply unit  53  having a cleaning liquid outlet  53   a  which is oriented from a center of the substrate W toward a peripheral portion of the substrate W with an elevation angle of not more than 45° from a surface of the substrate W. The cleaning liquid supply unit  53  supplies a cleaning liquid to the surface of the substrate W at a flow velocity of not less than 0.1 m/s.

FIELD OF THE INVENTION

The present invention relates to a substrate processing apparatus and asubstrate processing method suitable for use in an etching apparatuswhich etches a thin film formed on a peripheral portion of a substrate.The present invention also relates to a substrate processing apparatusand a substrate processing method suitable for use in a cleaningapparatus which performs a cleaning process on a substrate which hasbeen etched.

DESCRIPTION OF THE RELATED ART

In recent years, instead of using aluminum or aluminum alloys as amaterial for forming interconnection circuits on a substrate such as asemiconductor wafer, there is an eminent movement towards using copper(Cu) which has a low electric resistivity and high electromigrationendurance. Copper interconnects are generally formed by filling copperinto fine recesses formed in a surface of the substrate. There are knownvarious techniques for forming such copper interconnects, including CVD,sputtering, and plating. According to any such technique, a copper filmis formed on a substantially entire surface of a substrate, followed byremoval of unnecessary copper by chemical mechanical polishing (CMP).

Copper can be easily diffused into a silicon oxide film during asemiconductor fabrication process, thus impairing the electricinsulation of the silicon oxide film. Therefore, the unnecessary copper,which has been formed on a portion other than circuits, needs to becompletely removed from the substrate. Particularly, if the copperformed or deposited on a peripheral portion (including edge portion andbevel portion) of the substrate is rubbed off onto an arm of a transferrobot or a substrate storage cassette, such copper is diffused to causecontamination in subsequent processes, resulting in so-called crosscontamination. Therefore, the copper formed or deposited on theperipheral portion of the substrate is required to completely be removedimmediately after the copper film growing process or the CMP process isperformed.

Thus, an etching process has been widely practiced to remove a copperfilm formed or deposited on a peripheral portion of a substrate bysupplying a processing liquid (an etching liquid) onto the substrate.The etching process is performed in such a manner that the substrate isrotated in a chamber and the processing liquid is supplied onto theperipheral portion of the substrate which is being rotated. Theprocessing liquid, which has been supplied onto the substrate, reactswith the copper film on the substrate to remove the copper film, andthen recovered for reuse in the subsequent etching process.

However, in the conventional etching method, the processing liquid issupplied from a position spaced from the substrate by a certaindistance. Accordingly, the processing liquid impinges on the substrateand is scattered, thus causing contamination of an atmosphere in thechamber which requires a high cleanliness. Further, in the conventionalmethod, the processing liquid is continuously supplied so as to replacethe processing liquid on the substrate with a new cleaning liquid.However, of all the processing liquid which has been supplied, only asmall amount of the processing liquid is used in etching. Therefore, itis required to supply the processing liquid onto the substrate with agreatly larger amount than is required in the actual etching process.Accordingly, there is a need to reduce the amount of the processingliquid to be used.

Further, in a conventional cleaning process performed after the etching,generally, a large amount cleaning liquid is supplied onto the entiresurface of the substrate so as to wash out the processing liquid (theetching liquid) remaining on the peripheral portion of the substrate.Accordingly, although only the peripheral portion is required to becleaned, the cleaning liquid is supplied to a portion which is notrequired to be cleaned. If a large amount of the cleaning liquid issupplied onto the substrate, the cleaning liquid containing the etchingliquid is spattered on the surface of the substrate or scattered in thechamber, thus contaminating a portion of the substrate which is not atarget area to be etched. Further, the cleaning liquid is spattered on awall surface of the chamber, thus causing the contamination of theatmosphere in the chamber.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above drawback. It istherefore a first object of the present invention to provide a substrateprocessing apparatus and a substrate processing method which can supplya processing liquid onto a substrate without causing the processingliquid to be scattered so that a clean atmosphere in a chamber can bemaintained, and can reduce an amount of the processing liquid to beused.

It is a second object of the present invention to provide a substrateprocessing apparatus and a substrate processing method which can supplya cleaning liquid only to a necessary area of the substrate withoutcausing the cleaning liquid to be scattered so that a clean atmospherein a chamber can be maintained, and can reduce an amount of the cleaningliquid to be used.

In order to achieve the above object, the present invention provides asubstrate processing apparatus comprising: a substrate holder forholding a substrate substantially horizontally and rotating thesubstrate; and a processing liquid supply unit for supplying aprocessing liquid onto a peripheral portion of the substrate which isbeing rotated in such a manner that the processing liquid is stationarywith respect to the substrate.

According to the present invention having such a structure, theprocessing liquid can be supplied onto the substrate without beingscattered. As a result, a clean atmosphere in the chamber can bemaintained, and an efficiency of reaction between the processing liquidand a thin film can be improved, thus enabling a reduction in an amountof the processing liquid to be used.

In a preferred aspect of the present invention, the substrate processingapparatus comprises a processing liquid removal unit for removing theprocessing liquid from the substrate.

In a preferred aspect of the present invention, the processing liquidremoval unit sucks the processing liquid on the substrate.

With this structure, an amount and a presence area of the processingliquid staying on the substrate can be kept constant. Further, most ofthe processing liquid is removed by the processing liquid removal unitand only a small amount of the processing liquid flows out of thesubstrate. Therefore, it is possible to prevent contamination of theatmosphere in the chamber.

In a preferred aspect of the present invention, the processing liquidremoval unit comprises a gas-liquid separator for separating the suckedprocessing liquid and a gas from each other.

In a preferred aspect of the present invention, the substrate processingapparatus comprises a recovery unit for recovering the processing liquidwhich has been separated by the gas-liquid separator so as to supply therecovered processing liquid to the processing liquid supply unit.

With this structure, the processing liquid can be recovered for reuse,and hence a total amount of the processing liquid to be used can bereduced.

In a preferred aspect of the present invention, the substrate processingapparatus comprises a plurality of the processing liquid supply units.

In a preferred aspect of the present invention, the substrate processingapparatus comprises a plurality of the processing liquid removal units.

In this case, for example, if a first processing liquid supply unit isdisposed above the peripheral portion of the substrate and a secondprocessing liquid supply unit is disposed radially outwardly of thesubstrate, a circumferential portion (a side portion) and the peripheralportion of the substrate can be processed securely, and hence an area tobe processed can be accurately processed.

In a preferred aspect of the present invention, the substrate processingapparatus comprises a purge mechanism for supplying an inert gas to asurface of the substrate.

According to another aspect of the present invention, there is provide asubstrate processing method comprising: holding a substratesubstantially horizontally and rotating the substrate; supplying aprocessing liquid onto a peripheral portion of the substrate which isbeing rotated in such a manner that the processing liquid is stationarywith respect to the substrate; and sucking the processing liquid on thesubstrate.

According to another aspect of the present invention, there is provide asubstrate processing apparatus comprising: a substrate holder forholding a substrate substantially horizontally and rotating thesubstrate; and a cleaning liquid supply unit having a cleaning liquidoutlet which is oriented from a center of the substrate toward aperipheral portion of the substrate with an elevation angle of not morethan 45° from a surface of the substrate; wherein the cleaning liquidsupply unit supplies a cleaning liquid to the surface of the substrateat a flow velocity of not less than 0.1 m/s.

According to the present invention having such a structure, the cleaningliquid can be supplied only to a necessary area of the substrate withoutbeing scattered. As a result, a clean atmosphere in the chamber can bemaintained. Further, since the cleaning liquid is supplied only to thenecessary area, an amount of the cleaning liquid to be used can bereduced.

In a preferred aspect of the present invention, the cleaning liquidsupply unit is disposed closely to the surface of the substrate. Withthis structure, the cleaning liquid can be prevented from beingscattered, and the area necessary to be cleaned can be cleanedefficiently.

In a preferred aspect of the present invention, the substrate processingapparatus comprises a receiving unit disposed in the same plane as thesurface of the substrate and opens toward an area of the substrate wherethe cleaning liquid is supplied to, the cleaning liquid being receivedby the receiving unit and recovered through the receiving unit.

With this structure, the cleaning liquid, which has cleaned thenecessary area, is recovered by the receiving unit. Therefore, thecleaning liquid can be prevented from being scattered in the chamber,and the recovered cleaning liquid can be recycled.

According to another aspect of the present invention, there is provide asubstrate processing method comprising: providing a cleaning liquidoutlet which is oriented from a center of a substrate toward aperipheral portion of the substrate with an elevation angle of not morethan 45° from a surface of the substrate; and supplying a cleaningliquid at a flow velocity of not less than 0.1 m/s so as to clean atleast one of a front surface and a back surface of the substrate whichis being rotated.

According to another aspect of the present invention, there is provide asubstrate processing method comprising: supplying a processing liquid toa peripheral portion of a substrate which is being rotated; andsupplying a cleaning liquid to an area including the peripheral portionof the substrate which has been processed by the processing liquid so asto remove the processing liquid remaining on the peripheral portion ofthe substrate, the cleaning liquid being supplied from a cleaning liquidoutlet which is oriented from a center of the substrate toward theperipheral portion of the substrate with an elevation angle of not morethan 45° from a surface of the substrate.

According to the present invention, since the cleaning liquid issupplied only to the necessary area without being scattered, it ispossible to prevent contamination of a portion of the substrate causedby the remaining processing liquid sputtered on such a portionunnecessary to be etched. Further, such prevention of the contaminationin the chamber can eliminate contamination of the substrate which wouldoccur during or after the processing and can also eliminatecontamination of a substrate which would occur during a subsequentprocessing.

In a preferred aspect of the present invention, the cleaning liquid issupplied from the cleaning liquid outlet toward the peripheral portionof the substrate in a direction substantially parallel to the surface ofthe substrate.

In a preferred aspect of the present invention, the substrate processingmethod comprises receiving the cleaning liquid by a receiving unit whichis disposed in the same plane as the surface of the substrate and openstoward the area of the substrate where the cleaning liquid is suppliedto; and recovering the cleaning liquid through the receiving unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a substrate processingapparatus, which is applied to an etching apparatus, according to afirst embodiment of the present invention;

FIG. 2A is a perspective view showing an etching section of thesubstrate processing apparatus (the etching apparatus) according to thefirst embodiment of the present invention;

FIG. 2B is a side view showing the etching section in FIG. 2A;

FIG. 2C is a plan view showing the etching section in FIG. 2A;

FIGS. 3A and 3B are side views showing another examples of a chemicalliquid supply unit of the substrate processing apparatus according tothe first embodiment of the present invention;

FIG. 4 is a schematic view showing a gas-liquid separator of thesubstrate processing apparatus according to the first embodiment of thepresent invention;

FIG. 5A is a schematic view showing the gas-liquid separator and arecovery unit of the substrate processing apparatus according to thefirst embodiment of the present invention;

FIG. 5B is a schematic view showing another examples of the gas-liquidseparator and the recovery unit;

FIG. 6 is a cross-sectional view showing a substrate processingapparatus, which is applied to an etching apparatus, according to asecond embodiment of the present invention;

FIG. 7 is a perspective view showing roll chucks and the etching sectionof the substrate processing apparatus (the etching apparatus) accordingto the second embodiment of the present invention;

FIG. 8 is a side view showing a chemical liquid supply unit of asubstrate processing apparatus, which is applied to an etchingapparatus, according to a third embodiment of the present invention;

FIG. 9A is a side view showing a chemical liquid supply unit of asubstrate processing apparatus, which is applied to an etchingapparatus, according to a fourth embodiment of the present invention;

FIG. 9B is a plan view showing another examples of the chemical liquidsupply unit and a chemical liquid removal unit of the substrateprocessing apparatus (the etching apparatus) according to the fourthembodiment of the present invention;

FIG. 10A is a side view showing a substrate processing apparatus, whichis applied to a cleaning apparatus, according to a fifth embodiment ofthe present invention;

FIG. 10B is a plan view showing an essential part of the substrateprocessing apparatus (the cleaning apparatus) in the FIG. 10A;

FIG. 11 is a side view showing a modification example of the substrateprocessing apparatus (the cleaning apparatus) according to the fifthembodiment of the present invention;

FIG. 12A is a side view showing an essential part of a substrateprocessing apparatus, which is applied to a cleaning apparatus,according to a sixth embodiment of the present invention;

FIG. 12B is a cross-sectional view showing an essential part of thesubstrate processing apparatus (the cleaning apparatus) in FIG. 12A;

FIG. 13 is a cross-sectional view showing a peripheral portion of thesubstrate in a cleaning process; and

FIG. 14 is a plan view showing a copper plating apparatus incorporatinga substrate processing apparatus, which is applied to an etchingapparatus, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described with reference tothe drawings. In the respective drawings, like or corresponding partsare denoted by the same reference numerals or similar referencenumerals, and will not be described repetitively. The embodiments willbe described hereinafter for the purpose of illustrating the presentinvention, and it should be understood that the present invention is notlimited to the embodiments which will be described below.

FIG. 1 is a cross-sectional view showing a substrate processingapparatus, which is applied to an etching apparatus, according to afirst embodiment of the present invention. A chamber 1 for accommodatinga wafer W comprises a cylindrical chamber body 1 a, and a chamber cover2 for covering an upper end of the chamber body 1 a. The chamber body 1a extends vertically, and a lower end thereof is covered with a bottomportion 1 b. The chamber cover 2 has a reverted-dish shape and coversthe upper end of the chamber body 1 a. The upper end of the chamber body1 a and a peripheral edge of the chamber cover 2 are contactedhermetically with each other so that an interior space of the chamber 1can be sealed from the exterior.

The bottom portion 1 b is slightly inclined with respect to a horizontalplane, and a discharge pipe 3 for discharging both a gas and a liquid isprovided on a lowermost portion of the slope, i.e., a portion connectingthe bottom portion 1 b and the chamber body 1 a.

An open mouth 2 a is formed in a central portion of the chamber cover 2,and an upper shaft 6 extends vertically to pass through the open mouth 2a. The upper shaft 6 has a circular-plate-like flange 6 a at an upperedge thereof. The open mouth 2 a of the chamber cover 2 and the flange 6a are hermetically connected to each other by a bellows-like(accordion-like) flexible joint 7. An introduction pipe 9 is provided soas to extend through a central portion of the upper shaft 6. Thisintroduction pipe 9 is connected to an inert gas supply source 12 sothat an inert gas such as a nitrogen gas (N₂) or an argon (Ar) issupplied to a surface of the wafer W through the introduction pipe 9.

The chamber cover 2 and the upper shaft 6 are coupled to each other by acoupling member (not shown). This coupling member has a drive mechanism(not shown) for moving the upper shaft 6 with respect to the chambercover 2, so that a relative position between the chamber cover 2 and theupper shaft 6 can be adjusted by the drive mechanism. Theabove-mentioned flexible joint 7 is expanded and contracted inaccordance with a change in the relative position between the chambercover 2 and the upper shaft 6, thus keeping the interior space of thechamber 1 gas-tight.

An upper disk 10 in the form of a circular plate is attached to a lowerend of the upper shaft 6 and disposed in a horizontal state. The upperdisk 10 is disposed in such a state that a lower surface thereof facesthe surface of the circular wafer W, which is a substrate to beprocessed, and is parallel to the surface of the wafer W. A gap Sbetween the lower surface of the upper disk 10 and the upper surface ofthe wafer W should preferable be as small as possible, and isappropriately adjusted in the range of 0.5 to 20 mm, for example. Thisgap S is adjusted preferably in the range of about 0.8 to 10 mm, morepreferably in the range of about 1 to 4 mm, so that the inert gassupplied through the introduction pipe 9 flows uniformly over thesurface of the wafer W. By adjusting the gap S, it is possible toprotect the wafer W with a relatively small amount of the inert gas. Theadjustment of the gap S is performed by adjusting the relative positionbetween the upper shaft 6 and the chamber cover 2. The upper shaft 6,the upper disk 10, and the inert gas supply source 12 constitute a purgemechanism.

Inside the chamber 1, there is disposed a vacuum chuck (a substrateholder) 11 for holding the wafer W substantially horizontally androtating the wafer W. The vacuum chuck 11 has a through-hole 11 a formedtherein and communicating with a vacuum source (not shown), and thisthrough-hole 11 a communicates with an opening portion 11 b formed in anupper end of the vacuum chuck 11. The wafer W is placed on an uppersurface of the vacuum chuck 11, and is attracted to and held by thevacuum chuck 11 due to a vacuum produced by the vacuum source. Further,the vacuum chuck 11 is coupled to a drive source (not shown) forrotating the vacuum chuck 11, so that the wafer W attracted to and heldby the vacuum chuck 11 is rotated by the drive source together with thevacuum chuck 11. A rotational speed of the wafer W is required to below. Specifically, the rotational speed of the wafer W is not more than500 min⁻¹, preferably in the range of 5 to 200 min⁻¹.

Next, an etching section incorporated in the substrate processingapparatus (etching apparatus) according to the present embodiment willbe described with reference to FIG. 2. FIG. 2A is a perspective viewshowing an etching section of the substrate processing apparatusaccording to the present embodiment, FIG. 2B is a side view showing theetching section in FIG. 2A, and FIG. 2C is a plan view showing theetching section in FIG. 2A.

The etching section comprises a chemical liquid supply unit (aprocessing liquid supply unit) 15 for supplying a chemical liquid (aprocessing liquid) to the wafer W, and a chemical liquid removal unit (aprocessing liquid removal unit) 20 for removing the chemical liquid fromthe wafer W. The chemical liquid supply unit 15 comprises a supplynozzle 16 for supplying the chemical liquid onto a peripheral portion ofthe wafer W, a chemical liquid introduction pipe 17 connected to thesupply nozzle 16, and a chemical liquid storage tank 18 connected to thechemical liquid introduction pipe 17. As shown in FIG. 2B, the supplynozzle 16 has an open end 16 a positioned closely to the peripheralportion of the wafer W so that the chemical liquid stored in thechemical liquid storage tank 18 is supplied from the open end 16 a ofthe supply nozzle 16 to the peripheral portion of the wafer W throughthe chemical liquid introduction pipe 17.

The peripheral portion of the wafer is a peripheral area of a waferwhere no circuits are formed thereon, or a peripheral area of a waferwhere circuits are formed thereon, but are not used for a deviceeventually. In this embodiment, the chemical liquid for etching a copperfilm is used as a processing liquid. Therefore, the chemical liquidsupply unit 15 and the chemical liquid removal unit 20 serve as aprocessing liquid supply unit and a processing liquid removal unit,respectively.

The chemical liquid supplied from the chemical liquid supply unit 15comprises a liquid mixture containing at least one of mineral acid andorganic acid, and further containing at least one of hydrogen peroxide(H₂O₂) water and ozone (O₃) water, each of which serves as an oxidizingagent. Hydrofluoric acid (HF), hydrochloric acid (HCl), nitric acid(HNO₃), sulfuric acid (H₂SO₄), or the like may be used as the mineralacid. Acetic acid, formic acid, oxalic acid, or the like may be used asthe organic acid.

In a case where a ruthenium film is an object to be etched, astrong-alkali oxidizing agent solution comprising a solution of ahalogenated oxygen acid salt such as hypochlorite, chlorite, or bromatemay be used as the chemical liquid (the processing liquid) supplied fromthe chemical liquid supply unit 15. Alternatively, a mixed solution ofan alkaline agent containing e.g. an organic alkali such as ammonia,tetramethylammonium hydroxide, or trimethylamine, and an oxidizing agentsuch as bromine, iodine, chlorine dioxide, or ozone may be used as thechemical liquid (processing liquid).

In this embodiment, a flow rate and flow velocity of the chemical liquidsupplied from the supply nozzle 16 are set to low. Specifically, theflow rate of the chemical liquid should preferably be not more than 100ml/min, more preferably be 20 ml/min, furthermore preferably be not morethan 5 ml/min. A distance D between the open end 16 a of the supplynozzle 16 and the surface of the wafer W should preferably be not morethan 5 mm, more preferably be not more than 1 mm.

In this manner, because a small amount of the chemical liquid issupplied from a position close to the wafer onto the wafer which isbeing rotated at a low speed, the chemical liquid on the wafer isstationary with respect to the wafer. “The chemical liquid is stationarywith respect to the wafer” means that the chemical liquid, which hasbeen supplied from the fixedly-positioned chemical liquid supply unit 15onto the wafer being rotated, stays on a point where the chemical liquidis contacted with the wafer, and is relatively stationary when viewedfrom the wafer. Specifically, the chemical liquid supplied onto thewafer is not moved in the rotating direction of the wafer and does notflow out of the wafer due to a centrifugal force. Therefore, accordingto the present embodiment, the chemical liquid stays on the waferwithout flowing out the wafer, and hence the chemical liquid is kept incontact with the wafer for a longer period time than ever, thus enablinga reduction in an amount of the chemical liquid to be used.

As shown in FIG. 3A, the supply nozzle 16 may be constructed to be movedin the radial direction of the wafer W. With this structure, a processtarget area can be adjusted as needed. The process target area is aperipheral portion of a wafer and is also an area (an edge cut width) tobe processed. Generally, the process target area is set to an areaextending radially inwardly about several millimeters, e.g., in therange of 2 to 5 mm, from a circumferential edge (side portion) of awafer. Further, as shown in FIG. 3B, the supply nozzle 16 may beretreated from the wafer W after the wafer W is processed or when thewafer W is to be transferred out. With this structure, the wafer can beeasily transferred in and out.

The chemical liquid supplied from the chemical liquid supply unit 15 tothe wafer W is removed from the wafer W by the chemical liquid removalunit 20. As shown in FIG. 2A, this chemical liquid removal unit 20comprises a suction nozzle 21, and a suction source 23 connected to thesuction nozzle 21 through a chemical liquid delivery pipe 22. Thissuction nozzle 21 has a suction mouth (not shown) which is located atthe same radial position as the open end 16 a of the supply nozzle 16with respect to the radial direction of the wafer. Therefore, as shownin FIG. 2C, as the wafer W is rotated, the chemical liquid which hasbeen supplied from the chemical liquid supply unit 15 to the wafer W istransferred to the suction mouth of the suction nozzle 21, and thensucked and removed by the suction nozzle 21.

The suction nozzle 21 and the wafer W are kept in non-contact with eachother. In order to improve an efficiency of sucking the chemical liquid,the suction mouth of the suction nozzle 21 is preferably positioned asclosely to the wafer W as possible. A vacuum pump, an ejector, or thelike may be used as the suction source 23.

FIG. 4 is a schematic view showing a gas-liquid separator of thesubstrate processing apparatus (the etching apparatus) according to thepresent embodiment.

As show in FIG. 4, a gas-liquid separator 27 is provided on the chemicalliquid delivery pipe 22. A mixture of the chemical liquid and a gassucked through the suction nozzle 21 by the suction source 23 isintroduced into the gas-liquid separator 27, and only the chemicalliquid is stored in the gas-liquid separator 27. On the other hand, thegas introduced into the gas-liquid separator 27 is drawn by the suctionsource 23. A path extending from the suction nozzle 21 to the suctionsource 23 is secured in gas-tightness in order to improve the suctionefficiency of the chemical liquid. A vacuum gauge and a vacuum pressureadjustment valve may be installed in the gas-liquid separator 27 so thata suction force is controlled by adjusting a vacuum pressure.

FIG. 5A is a schematic view showing the gas-liquid separator and arecovery unit of the substrate processing apparatus according to thepresent embodiment, and FIG. 5B is a schematic view showing anotherexamples of the gas-liquid separator and the recovery unit.

As shown in FIG. 5A, a recovery unit 32 is connected to a bottom portionof the gas-liquid separator 27, so that the chemical liquid which hasbeen separated by the gas-liquid separator 27 is introduced to therecovery unit 32. The chemical liquid introduced to the recovery unit 32is filtered by a filter (not shown), and then returned to theabove-mentioned chemical liquid storage tank 18 of the chemical liquidsupply unit 15. As shown in FIG. 5B, the gas-liquid separator 27 mayhave a level sensor 28 for detecting a liquid surface level of thestored chemical liquid. Further, after the chemical liquid is sucked andremoved from the wafer or when the liquid surface level reaches apredetermined level, a valve may be opened to deliver the chemicalliquid to the recovery unit 32.

In this manner, the chemical liquid supplied to the wafer W is recoveredthrough the chemical liquid removal unit 20, the gas-liquid separator27, and the recovery unit 32, and is then supplied from the chemicalliquid supply unit 15 onto the wafer W again. In this embodiment, thechemical liquid which has been supplied to the wafer W is sucked as itis on the wafer W, and hence the chemical liquid can be recoveredwithout being substantially diluted. That is, degrees of the dilution ofthe chemical liquid and the contamination are greatly lowered, comparedwith a conventional method in which a chemical liquid which has flowedout of the wafer is recovered from a discharge port of a chamber.Further, in this embodiment, a concentration of the chemical liquidwhich has been recovered by the recovery unit 32 is not loweredsubstantially, and hence the processing capability of the chemicalliquid to be reused can be maintained.

Next, operation of the substrate processing apparatus (the etchingapparatus) according to the present embodiment will be described.

In FIG. 1, first, a wafer W to be processed is held and rotated by thevacuum chuck 11. Then, the etching liquid, such as a mixed liquid of,for example, hydrofluoric acid and hydrogen peroxide is supplied fromthe supply nozzle 16 of the chemical liquid supply unit 15 onto theperipheral portion of the wafer W which is being rotated. At this time,the inert gas such as a nitrogen gas is supplied from the introductionpipe 9 toward the surface of the wafer W.

Since the inert gas supplied from the introduction pipe 9 flows in thedirection from the central portion toward the peripheral portion of thewafer W, it is possible to prevent a chemical liquid atmosphere and mistfrom flowing toward the central portion of the wafer W. Therefore, it ispossible to prevent the surface of the wafer W from being deteriorateddue to the chemical liquid atmosphere and the mist, and it is alsopossible to prevent the copper film from being oxidized due to reactionbetween oxygen in the atmospheric air and the mist. A supply amount ofthe inert gas is set such that the chemical liquid atmosphere and themist do not flow toward the central portion of the wafer and thechemical liquid supplied onto the peripheral portion of the wafer W doesnot flow out of the wafer.

The chemical liquid is supplied to the wafer W being rotated in such amanner that the chemical liquid on the wafer W is stationary withrespect to the wafer W. As the wafer W is rotated, the chemical liquidon the wafer W is transferred to the suction nozzle 21 of the chemicalliquid removal unit 20, and then sucked and removed by the suctionnozzle 21. Specifically, the chemical liquid is present on the wafer Wduring a period of time from when the chemical liquid is supplied fromthe chemical liquid supply unit 15 to when the chemical liquid isremoved by the chemical liquid removal unit 20, and the etching processis performed during this period of time. The chemical liquid which hasbeen sucked by the chemical liquid removal unit 20 is delivered to thechemical liquid supply unit 15 via the gas-liquid separator 27 and therecovery unit 32, and is then supplied to the wafer W again from thechemical liquid supply unit 15. After the etching process is finished,ultrapure water is supplied to the wafer W from a non-illustratedcleaning liquid supply unit so as to wash (rinse) out the chemicalliquid which has been used in the etching process.

Next, a substrate processing apparatus, which is applied to an etchingapparatus, according to a second embodiment of the present inventionwill be described below with reference to FIGS. 6 and 7. Structure andoperation of this embodiment, which will not be described, are identicalto those of the first embodiment.

FIG. 6 is a cross-sectional view showing a substrate processingapparatus according to the present embodiment. FIG. 7 is a perspectiveview showing roll chucks and the etching section of the substrateprocessing apparatus according to the present embodiment.

The bottom portion 1 b has six openings (not shown), and six roll chucks35 a to 35 f for holding a wafer W horizontally extend verticallythrough the six openings. The six roll chucks 35 a to 35 f are rotatedsynchronously, so that the wafer W is rotated at a low speed. Thechemical liquid supply unit 15 and the chemical liquid removal unit (theetching section) 20 are disposed between the roll chuck 35 a and theroll chuck 35 f. A rotational speed of the wafer W rotated by the rollchucks 35 a to 35 f is the same as that in the first embodiment.

As illustrated in this embodiment, even in the case where the rollchucks 35 a to 35 f are used as the substrate holder, the chemicalliquid supply unit 15 and the chemical liquid removal unit 20 can bedisposed closely to the wafer W. Therefore, the chemical liquid can besupplied to the wafer W in such a manner that the chemical liquid isstationary with respect to the wafer W which is being rotated, and thechemical liquid can be removed from the wafer W.

Next, a third embodiment of the present invention will be described withreference to FIG. 8.

FIG. 8 is a side view showing a chemical liquid supply unit of asubstrate processing apparatus, which is applied to an etchingapparatus, according to the present embodiment.

As shown in FIG. 8, in this embodiment, a sponge 36 is attached to a tipend of the supply nozzle 16, so that the chemical liquid oozed from thesponge 36 is supplied to the peripheral portion of the wafer W. Thesponge 36 is kept in non-contact with the wafer W, and a distancebetween the sponge 36 and the wafer W is the same as that in the firstembodiment. Instead of the sponge, a porous material such as cloth maybe used.

Next, a fourth embodiment of the present invention will be describedwith reference to FIGS. 9A and 9B.

FIG. 9A is a side view showing a chemical liquid supply unit of asubstrate processing apparatus, which is applied to an etchingapparatus, according to the present embodiment. FIG. 9B is a plan viewshowing another examples of the chemical liquid supply unit and thechemical liquid removal unit of the substrate processing apparatus (theetching apparatus) according to the present embodiment.

As shown in FIG. 9A, a first supply nozzle 16A is disposed above theperipheral portion of a wafer W, and a second supply nozzle 16B isdisposed closely to the circumferential edge of the wafer W. Since thechemical liquids are supplied from the two supply nozzles 16A and 16Bwhich are arranged as described above, the processing area of the waferW can be controlled, and the peripheral portion and the circumferentialedge of the wafer W can be processed securely.

Further, as shown in FIG. 9B, two supply nozzles 16A and 16B and twosuction nozzles 21A and 21B may be arranged alternately in thecircumferential direction of the wafer W. In this case, the same type ofchemical liquid may be supplied from the respective supply nozzles 16Aand 16B, or different types of chemical liquids may be supplied from thesupply nozzles 16A and 16B, respectively. In any cases, the chemicalliquid supplied from the first supply nozzle 16A is sucked by the firstsuction nozzle 21A, and the chemical liquid supplied from the secondsupply nozzle 16B is sucked by the second suction nozzle 21B.

Although the chemical liquid which has been supplied onto the wafer W isremoved by the chemical liquid removal unit, a slight amount of thechemical liquid remains on the wafer W. Thus, the substrate processingapparatus has the cleaning liquid supply unit (not shown) for cleaning(rinsing) the wafer W. The cleaning liquid supply unit has a pluralityof nozzles disposed at a front side and back side of the wafer W, sothat the cleaning liquids (rinsing liquids) are supplied to the wafer Wfrom the nozzles. Ultrapure water is used as the cleaning liquid.

As described above, according to the present invention, a processingliquid can be supplied to a substrate without being scattered.Therefore, a clean atmosphere in the chamber can be maintained, and anefficiency of the reaction between the processing liquid and the wafercan be improved, thus enabling a reduction in an amount of theprocessing liquid to be used.

Next, a substrate processing apparatus, which is applied to a cleaningapparatus, according to a fifth embodiment of the present invention willbe described with reference to FIGS. 10A and 10B. FIG. 10A is a sideview showing an essential part of a substrate processing apparatus,which is applied to a cleaning apparatus, according to the presentembodiment, and FIG. 10B is a plan view showing an essential part of thesubstrate processing apparatus (the cleaning apparatus) in the FIG. 10A.

The substrate processing apparatus shown in FIGS. 10A and 10B isdisposed in the chamber (not shown) for performing an etching process ona copper film. This substrate processing apparatus may be used in boththe etching process and a cleaning process, or may serve as aseparate-type cleaning apparatus only for the cleaning process. Thesubstrate processing apparatus comprises a substrate holder 54, whichhas a main shaft 51 and a table 52, for holding a wafer (substrate) Wsubstantially horizontally and rotating the wafer W to be cleaned. Thewafer W is fixed to and held by an upper surface of the table 52 byvacuum attraction or the like. A cleaning liquid discharge nozzle(cleaning liquid supply unit) 53 is disposed near a front surface of thewafer W. The cleaning liquid discharge nozzle 53 has an outlet 53 awhich is oriented from a central portion toward a peripheral portion ofthe wafer W with an elevation angle θ of not more than 45° from thesurface of the wafer W. Therefore, an incident angle of the cleaningliquid L with respect to the surface of the wafer W is the angle θ ofnot more than 45°. The cleaning liquid L is supplied to a predeterminedtarget area to be cleaned at a flow velocity of not less than 0.1 m/s.The cleaning liquid discharge nozzle (cleaning liquid supply unit) 53may be disposed at a side of a back surface of the wafer W, or may bedisposed at both sides of the front and back surface of the wafer W.

The flow velocity of the cleaning liquid L is adjusted to apredetermined value by a supply equipment 57 having a cleaning liquidstorage tank, and then the cleaning liquid L is ejected from thecleaning liquid discharge nozzle 53. The cleaning liquid comprises arinsing liquid or a chemical liquid suitable for use in removing theremaining processing liquid (etching liquid) which has been used in theetching process.

Since the cleaning liquid is ejected toward the predetermined area to becleaned at an angle of not more than 45° from the surface the wafer W, avelocity component in a horizontal direction of the cleaning liquid islarger than a velocity component in a vertical direction. Thus, thecleaning liquid having a large velocity component in the horizontaldirection is supplied in the direction from the central portion towardthe peripheral portion of the wafer. Therefore, the processing liquid orthe like on the target area to be cleaned is quickly washed out from thewafer. Since the flow velocity of the cleaning liquid flowing from thecentral portion toward the peripheral portion of the wafer is largewhile the wafer is cleaned, the cleaning liquid can be quickly replacedwith a new cleaning liquid. Accordingly, an amount of the cleaningliquid to be used can be minimized, and an effective cleaning processcan be performed. Further, since the cleaning liquid is supplied only toa necessary area to be cleaned, the amount of the cleaning liquid can befurther reduced.

If the cleaning liquid being incident on the substrate has a largevelocity component in the vertical direction, the cleaning liquid isscattered due to impingement against the wafer. In this embodiment,because the incident angle of the cleaning liquid with respect to thesurface of the wafer is not more than 45°, the velocity component in thevertical direction of the cleaning liquid is low when the cleaningliquid impinges on the wafer, and hence it is possible to prevent thecleaning liquid from being scattered from the surface of the wafer.

From the above viewpoint, the incident angle (elevation angle) withrespect to the surface of the wafer should preferably be as small aspossible. Specifically, 30° or less is preferable, and 15° or less ismore preferable. Although the incident angle of 0° is ideal, thecleaning liquid discharge nozzle 53 cannot be disposed in contact withthe surface of the wafer. Therefore, the incident angle (elevationangle) is preferably set such that the incident direction of thecleaning liquid is as parallel to the surface of the wafer as possible.

From a viewpoint of increasing the velocity component in the horizontaldirection, the flow velocity of the cleaning liquid is an importantfactor. Table 1 shows a test result of a cleaning effect with a study ofelevation angles and flow velocities. In this table 1, the angles areput in a vertical direction, and the flow velocities are put in ahorizontal direction. A sign of “◯” in this table 1 shows that an goodcleaning result was obtained, and a sign of “X” shows that an goodcleaning result was not obtained. The rotational speed of the wafer was100 min⁻¹, and a distance between the target area to be cleaned and theoutlet of the cleaning liquid discharge nozzle is in the range of 30 to50 mm.

TABLE 1 θ 0.05 m/s 0.1 m/s 0.45 m/s 0.9 m/s 1.1 m/s 15° ◯ ◯ ◯ ◯ ◯ 25° X◯ ◯ ◯ ◯ 35° X ◯ ◯ ◯ ◯ 45° X X X ◯ ◯ 60° X X X X ◯ 75° X X X X X

As can be seen from the table 1, in a case of the cleaning liquid havinga flow velocity of 0.1 m/s, a good cleaning result was obtained at anelevation angle ranging from 15° to 35°. In a case of the cleaningliquid having a flow velocity of 1.1 m/s, a good cleaning result wasobtained at an elevation angle ranging from 15° to 60°. Therefore, whenthe cleaning liquid is supplied at an elevation angle of not more than45° from the surface of the wafer and the cleaning liquid is supplied tothe target area at a flow velocity of not less than 0.1 m/s, a goodcleaning result can be obtained. Particularly, the table 1 shows that asmall elevation angle is important in obtaining a good cleaning result.The flow velocity is given by dividing a flow rate of the cleaningliquid by an opening area of the outlet of the cleaning liquid dischargenozzle.

If the rotational speed of the wafer is not more than 500 min⁻¹, thecentrifugal force is small. Therefore, the cleaning liquid does not flowout of the wafer and thus stays on the wafer, and hence it is hard toreplace the cleaning liquid with a new cleaning liquid. Since thecleaning liquid is supplied from the inward side toward the outward sideof the wafer at a flow velocity of not less than 0.1 m/s, the cleaningprocess can be performed efficiently even when the wafer is rotated at alow speed.

It is preferable that the cleaning liquid discharge nozzle 53 ismovable. With this structure, the nozzle 53 can be disposed at a desiredposition for the target area, to be cleaned, of the wafer. In addition,after the cleaning process, the cleaning liquid discharge nozzle 53 canbe retreated from the wafer, so that the wafer can be easily transferredin and out.

FIG. 11 shows a modification example of an essential part of thesubstrate processing apparatus according to the present embodiment. Inthis example, cleaning liquid discharge nozzles 53-1 and 53-2 havingrespective outlets 53-1 a and 53-2 a are disposed at the front and backsides of the wafer, respectively, so that the front and back surfaces ofthe wafer W can be cleaned simultaneously. Because of such anarrangement, the substrate folder comprises chucks 58 which are broughtinto contact with the circumferential edge of the wafer W to hold androtate the wafer W. This structure allows the cleaning liquid dischargenozzles 53-1 and 53-2 to be disposed at the front and back sides of thewafer W, and hence, as described above, the front and back surfaces ofthe wafer W can be cleaned simultaneously. The cleaning liquid dischargenozzles 53-1 and 53-2 are not necessarily disposed symmetrically, andthe elevation angles and the positions thereof can be changed as neededdepending on the cleaning application.

FIG. 12A, FIG. 12B, and FIG. 13 show a substrate processing apparatus,which is applied to a cleaning apparatus, according to a sixthembodiment of the present invention. The substrate processing apparatus(the cleaning apparatus) of this embodiment comprises a substrate holderhaving chucks 61 a, 61 b, 61 c and 61 d for holding a wafer Wsubstantially horizontally and rotating the wafer W. Alternatively, arotating-table-type substrate holder as shown in FIG. 10A may be used.The substrate processing apparatus also comprises a processing unit 62for performing an etching process. The processing unit 62 supplies anetching liquid (a processing liquid) to a peripheral portion of thewafer W to remove a thin film such as a copper film formed on theperipheral portion.

This substrate processing apparatus further comprises a cleaning unit (acleaning liquid supply unit) 63 for washing out an etching liquidremaining on the etching process target area of the wafer W after theetching process is performed. The cleaning unit 63 supplies the cleaningliquid from its cleaning liquid outlet 63 a to an area “B” including anetching process target area “A”, i.e., the peripheral portion of thewafer W, so as to remove the processing liquid remaining on the area“B”. The cleaning liquid flows from the inward side toward theperipheral portion of the wafer W along the radial direction at anelevation angle of not more than 45°, which is set as small as possible,from the surface of the wafer W, thus forming a flow of the cleaningliquid. The cleaning liquid is supplied while the wafer W is beingrotated. A receiving unit 65 is disposed on an extended line of the flowof the cleaning liquid L which is supplied in the direction from thecentral portion to the peripheral portion of the wafer W, and openstoward the area of the wafer W where the cleaning liquid L is suppliedto. The receiving unit 65 is positioned on the same plane as the surfaceof the wafer W. As shown in FIG. 12 B, the receiving unit 65 has agutter-like shape and receives the cleaning liquid L which has flowedout of the peripheral portion of the wafer W. The processing liquidflowing on the receiving unit 65 is recovered through a non-illustrateddrain.

Next, operation of the substrate processing apparatus will be described.First, the wafer W is held and rotated by the chucks 61 a, 61 b, 61 cand 61 d. In this state, the etching liquid is supplied from theprocessing unit 62 to the peripheral portion of the wafer W, so that acopper film formed on the peripheral portion of the wafer W is removedby the etching liquid. This etching process forms the area “A” on thewafer W where the copper film (Cu) has been removed. Then, the area “B”including the area “A” is cleaned by the cleaning unit 63. In thiscleaning process, the cleaning liquid is supplied from the cleaning unit(cleaning liquid supply unit) 63 to the target area “B” to be cleaned.At this time, the cleaning liquid is supplied in the direction orientedfrom the central portion toward the peripheral portion of the wafer at aflow velocity of not less than 0.1 m/s with an incident angle θ from thesurface of the wafer W. It is preferable that the incident angle θ is assmall as possible, as indicated in the above-mentioned table 1. In orderto remove the processing liquid remaining on the area “A” where theetching process has been performed, the area “B” to be supplied with thecleaning liquid L is required to include the area “A”. In this case, itis preferable that the area “B” is as small as possible. If the area “B”is small, the amount of the cleaning liquid to be used can be reducedand the cleaning process can be performed efficiently.

By supplying the cleaning liquid L with an elevation angle θ, that is assmall as possible, at a sufficient flow velocity while rotating thewafer W at a relatively low speed, the area “B” can be cleanedefficiently and securely. According to this cleaning method, because thecleaning liquid is supplied only to the relatively small area while thewafer W is being rotated, the amount of the cleaning liquid to be usedcan be reduced greatly. Further, because the incident angle θ of thecleaning liquid with respect to the surface of the wafer W is small, itis possible to prevent the processing liquid from being scattered fromthe surface of the wafer W.

The cleaning liquid, which has been supplied to the peripheral portionof the wafer W, is received by the gutter-like receiving unit 65, and isrecovered through the non-illustrated drain. Therefore, the cleaningliquid that has flowed out the wafer W can be prevented from beingscattered in the chamber, and the cleaning liquid can be recovered forreuse.

Although certain embodiments of the present invention have beendescribed in detail, it should be understood that various modificationsmay be made without departing from the scope of the present invention.

As described above, according to the present invention, a cleaningliquid is supplied to a limited area such as a peripheral portion of asubstrate with a small elevation angle, an amount of the cleaning liquidto be used can be reduced. Further, it is possible to preventcontamination of the substrate due to spattering of the cleaning liquidand maintain a clean atmosphere in the chamber.

Next, a plating apparatus for performing copper plating on asemiconductor wafer will be described. This plating apparatus has asubstrate processing apparatus, which is applied to an etchingapparatus, according to the present invention.

As show in FIG. 14, the plating apparatus is disposed in a rectangularfacility 710, and is constituted so as to plate wafers (substrates) withcopper successively. The facility 710 has a partition wall 711 fordividing the facility 710 into a plating section 712 and a clean section713. Air can individually be supplied into and exhausted from each ofthe plating section 712 and the clean section 713. The partition wall711 has a shutter (not shown) capable of opening and closing. A pressureof the clean section 713 is lower than the atmospheric pressure andhigher than a pressure of the plating section 712. This can prevent theair in the clean section 713 from flowing out of the facility 710 andcan prevent the air in the plating section 712 from flowing into theclean section 713.

In the clean section 713, there are provided two loading and unloadingsections 715 for placing a substrate cassette thereon, and two cleaningunits 716 for cleaning (rinsing) a plated wafer with pure water anddrying the wafer. Further, a rotatable fixed-type first transfer robot717 for transferring a wafer is provided in the clean section 713. Forexample, the cleaning unit 716 has cleaning liquid supply nozzles forsupplying ultrapure water to both surfaces of a wafer, and spins thewafer at a high speed to dewater and dry the wafer.

On the other hand, in the plating section 712, there are provided twopretreatment units 721 for pretreating a surface of a wafer to be platedand reversing the pretreated wafer by an reverse mechanism 720, fourplating units 722 for plating a surface of a wafer with copper in such astate that the front surface of the wafer faces downwardly, and twofirst substrate stages 723 a and 723 b for holding a wafer placedthereon. Further, a rotatable mobile-type second transfer robot 724 fortransferring a wafer is provided in the plating section 712.

In this plating apparatus, in the clean section 713, there are providedtwo substrate processing apparatuses (etching apparatus) 725 for etchinga plated wafer with chemical liquid (processing liquid), and secondsubstrate stages 726 a and 726 b disposed between the substrateprocessing apparatuses 725 and the cleaning units 716. A rotatablefixed-type third transfer robot 727 for transferring a wafer is providedbetween the two substrate processing apparatuses 725.

One of the first substrate stages and one of the second substratestages, i.e., the first substrate stage 723 b and the second substratestage 726 b are constituted so as to clean the wafer with water. Each ofthe first substrate stage 723 b and the second substrate stage 726 b hasa reverse mechanism 720 for reversing a wafer.

Thus, the first transfer robot 717 transfers a wafer between thesubstrate cassettes placed on the loading and unloading sections 715,the cleaning units 716, and the second substrate stages 726 a and 726 b.The second transfer robot 724 transfers a wafer between the firstsubstrate stages 723 a and 723 b, the pretreatment units 721, and theplating units 722. The third transfer robot 727 transfers a waferbetween the first substrate stages 723 a and 723 b, the substrateprocessing apparatuses 725, and the second substrate stages 726 a and726 b.

A container 728 for accommodating wafers for trial operation is disposedin the facility 710, and located below the first substrate stage 723 a.The second transfer robot 724 takes out a wafer for trial operation fromthe container 728, and returns it to the container 728 after trialoperation. Thus, the container 728 provided in the facility 710 foraccommodating the wafers for trial operation can eliminate contaminationor lowering of the throughput caused by introduction of wafers for trialoperation from the outside when trial operation is conducted.

As long as the wafers for trial operation can be taken out from thecontainer 728 and returned to the container 728 by any of the transferrobots, the container 728 may be placed anywhere in the facility 710.However, when the container 728 is disposed in the vicinity of the firstsubstrate stage 723 a, the trial operation can be conducted in such amanner that a wafer for trial operation is pretreated, plated, cleanedand dried, and then returned to the container 728.

The transfer robot 717 has two recess-type hands. The upper hand is usedfor handling a dry wafer and the lower hand is used for handling a wetwafer. Each of the transfer robots 724 and 727 has two recess-type handswhich are used for handling a wet wafer. The hands of the transferrobots are not limited to those types described above.

Next, an operation flow for processing a wafer in the plating apparatuswill be described below. The wafers are accommodated in the cassette insuch a state that the front surface of the wafer (surface on whichdevices are formed, i.e., surface to be processed) faces upwardly, andthe cassette is placed on the loading and unloading section 715. Thefirst transfer robot 717 takes out a wafer from the cassette, moves tothe second substrate stage 726 a, and places the wafer on the secondsubstrate stage 726 a. Then, the third transfer robot 727 transfers thewafer from the second substrate stage 726 a to the first substrate stage723 a. Thereafter, the second transfer robot 724 receives the wafer fromthe first substrate stage 723 a and transfers the wafer to thepretreatment unit 721. After the pretreatment of the wafer is completedin the pretreatment unit 721, the wafer is reversed by the reversemechanism 720 so that the front surface of the wafer faces downwardly,and then transferred to the second transfer robot 724. The secondtransfer robot 724 transfers the wafer to a head of the plating unit 22.

After the wafer is plated and liquid on the wafer is removed in theplating unit 722, the wafer is received by the second transfer robot724, which transfers the wafer to the first substrate stage 723 b. Thewafer is reversed by the reverse mechanism 720 provided at the firstsubstrate stage 723 b so that the front surface faces upwardly, and thentransferred to the substrate processing apparatus 725 by the thirdtransfer robot 727. The wafer is etched by the substrate processingapparatus 725, and then transferred to the second substrate stage 726 bby the third transfer robot 727. Next, the first transfer robot 717receives the wafer from the second substrate stage 726 b, and transfersthe wafer to the cleaning unit 716. In the cleaning unit 716, the waferis rinsed with pure water (includes deionized water) and thenspin-dried. The dried wafer is returned to the substrate cassette placedon the loading and unloading section 715 by the first transfer robot717.

1-9. (canceled)
 10. A substrate processing apparatus comprising: asubstrate holder for holding a substrate substantially horizontally androtating the substrate; and a cleaning liquid supply unit having acleaning liquid outlet which is oriented from a center of the substratetoward a peripheral portion of the substrate with an elevation angle ofnot more than 45° from a surface of the substrate; wherein said cleaningliquid supply unit supplies a cleaning liquid to the surface of thesubstrate at a flow velocity of not less than 0:1 m/s.
 11. A substrateprocessing apparatus according to claim 10, comprising a receiving unitdisposed in the same plane as the surface of the substrate and openstoward an area of the substrate where the cleaning liquid is suppliedto, the cleaning liquid being received by said receiving unit andrecovered through said receiving unit.
 12. A substrate processingapparatus according to claim 10, wherein said cleaning liquid supplyunit is disposed closely to the surface of the substrate.
 13. Asubstrate processing apparatus according to claim 12, comprising areceiving unit disposed in the same plane as the surface of thesubstrate and opens toward an area of the substrate where the cleaningliquid is supplied to, the cleaning liquid being received by saidreceiving unit and recovered through said receiving unit. 14-17.(canceled)